Dynamic Behaviour of the Carillon Tower in Castel San Pietro Terme, Italy Azzara R. M., Girardi M., Padovani C., Pellegrini D. This paper presents the experimental investigations conducted on the carillon tower of the Santissimo Crocifsso Sanctuary in Castel San Pietro (Bologna, Italy) and the analysis of data collected by using velocimeters and accelerometers installed on the structure. The main goal is to assess the effects of the swinging bells on the dynamic behaviour of the tower. The paper's novelty relies on the kind of structure monitored and the originality of the experiments. The structure is a rare example of a carillon tower, with fifty-five bells of different sizes, subjected to a careful measurement campaign never carried out before. Six experiments were conducted selectively by activating the bells to measure the tower's response induced by different vibration sources and determine the peak velocities recorded by using instruments at different heights. Two ambient vibration tests complemented the six experiments. The carillon's action induces low velocities on the tower, while experiments involving the bells swinging in the upper chamber produce the highest velocity values in the swinging direction; these values are more significant than those induced by the carillon alone. The most robust action is induced on the tower when all the bells (carillon plus swinging bells) ring. The experimental results are complemented by numerical simulations of the dynamic behaviour of the tower subjected to the action of a swinging bell.Source: Structural control and health monitoring (Online) (2023). doi:10.1155/2023/1045234 DOI: 10.1155/2023/1045234 Metrics:
Analisi del collasso di strutture ad arco in muratura: indagini sperimentali su modelli in scala E. Casassa, (relatori: Barsotti R., Barsi F., Girardi M., Padovani C., Bennati S. ) La tesi vuole analizzare il comportamento sperimentale di modelli in scala di arco sottoposti a carichi pseudostatici incrementali. I modelli degli archi sono ottenuti accostando, a secco, i conci ottenuti attraverso una stampante 3D.
L'azione sismica viene simulata come una forza statica d'inerzia, proporzionale alla massa. In questo senso, per applicare un pattern di carichi adeguato è stata prevista la costruzione di una tilting table.
I risultati sperimentali, raccolti sottoforma di moltiplicatori dei carichi orizzontali di collasso , vengono successivamente analizzati criticamente confrontandoli con i risultati teorici (trovati attraverso il teorema cinematico) ed i risultati forniti dal software di calcolo NOSA-ITACA.
Experimental investigations and numerical modelling: a fruitful interaction for the nonlinear dynamical analysis of masonry structures Azzara R. M., Girardi M., Padovani C., Pellegrini D. This paper describes the experiments carried out on a medieval masonry tower in the historic centre of Lucca and some finite element numerical simulations of the tower's experimental response. The Guinigi Tower, one of the most iconic monuments in Lucca, has been continuously monitored by high-sensitive seismic stations that recorded the structure's response to the dynamic actions of the surrounding environment. The monitoring campaign results have been analysed to show the effectiveness of dynamic monitoring as a valuable source of information on the structural properties of the tower. The dynamic analyses of the tower and the surrounding palace subjected to some seismic events recorded during the experiments have highlighted the capabilities of experiment-based finite element modelling. The calibration of the finite element model and the numerical analysis have been carried out by resorting to procedures developed at ISTI-CNR and able to consider the nonlinear behaviour of masonry materials.Source: Continuum mechanics and thermodynamics (Internet) (2023). doi:10.1007/s00161-023-01264-2 DOI: 10.1007/s00161-023-01264-2 Metrics:
Effects of temperature variations on the modal properties of masonry structures: an experimental-based numerical modelling approach D. Pellegrini D., Barontini A., Girardi M., Lourenço P. B., Masciotta M. G., Mendes N., Padovani C., Ramos L. F. Long-term ambient vibration monitoring campaigns show that environmental parameters (such as temperature, humidity, wind speed and direction) can influence the structures' static and dynamic behaviour. In particular, thermal variations can affect the modal characteristics of ancient masonry constructions. This work presents a procedure combining experimental and numerical steps to monitor, assess and model the dynamic behaviour of masonry structures subjected to thermal loads. The procedure is tested and validated through two numerical examples and the simulation of a full-scale masonry structure, the Mogadouro clock tower in Portugal, monitored with accelerometers and temperature and humidity sensors.Source: Structures (Oxford) 53 (2023): 595–613. doi:10.1016/j.istruc.2023.04.080 DOI: 10.1016/j.istruc.2023.04.080 Metrics:
Long-term monitoring of a masonry tower with wireless accelerometers Zini G., Marafini F., Monchetti S., Betti M., Facchini L., Bartoli G., Girardi M., Gurioli G., Padovani C., Pellegrini D. During the last decades, significant efforts have been made to define appropriate Structural Health Monitoring (SHM) frameworks based on the vibration signatures collected by accelerometers. Data-driven approaches are increasingly adopted for damage detection through the identification of anomalies in the distribution of the frequencies. This paper analyzes the long-term monitoring data acquired from a system installed on the Matilde tower in Livorno (Italy). The tower is a historic masonry structure monitored since the end of 2018 using a wireless sensor network developed during the MOSCARDO project.Source: COMPDYN 2023 - 9th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering, Athens, Greece, 12-14/06/2023
Numerical modelling of historical masonry structures with the finite element code NOSA-ITACA Girardi M., Padovani C., Pellegrini D., Porcelli M., Robol L. This chapter presents the finite element code NOSA-ITACA for static and modal analyses of masonry structures of architectural interest. NOSA-ITACA adopts the constitutive equation of masonrylike materials, which considers masonry a non-linear elastic material with zero tensile strength. The capability of modelling restoration and consolidation operations makes the code a helpful tool for maintaining historical buildings. In recent years, long-term vibration monitoring turned out to be an effective non-destructive technique to investigate the dynamic behaviour and check the health status of historical buildings. Changes in their dynamic properties, such as natural frequencies, can represent effective damage indicators. The latest NOSA-ITACA developments are oriented towards structural health monitoring. The availability of the experimental modal properties of a structure makes it possible to calibrate its finite element model via model updating procedures. In particular, the unknown structure's characteristics, such as materials' properties and boundary conditions, can be determined by solving a minimum problem whose objective function is expressed as the discrepancy between experimental frequencies and mode shapes and their numerical counterparts. Several case studies are presented to show the main features of NOSA-ITACA and its effectiveness in the conservation of architectural heritage.Source: Mathematical Modeling in Cultural Heritage. MACH 2021, edited by Bretti G., Cavaterra C., Solci M., Spagnuolo M., pp. 133–152, 2023 DOI: 10.1007/978-981-99-3679-3_9 Metrics:
Towards a cloud-based platform for structural health monitoring: implementation and numerical issues Croce T., Girardi M., Gurioli G., Padovani C., Pellegrini D. Structural Health Monitoring (SHM) is increasingly important in protecting and maintaining architectural heritage. Its main goal is to distinguish ordinary fluctuations in a building's response from other, possibly anomalous, behaviour. SHM starts setting sensors to measure accelerations or velocities and other environmental parameters over time at fixed points of the structure. The time series processing makes it possible to perform modal tracking and damage/anomaly detection while correlating dynamical and environmental parameters. In practice, these activities are conducted separately, using different numerical codes. Thus, the idea is to take the first step to distance from such practice, leveraging the MOSCARDO system, which encompasses a Wireless Sensor Network (WSN) and a platform designed according to a cloud architecture that provides services for storing and processing data from the WSN. We employ a code based on the Stochastic Subspace Identification (SSI) technique to improve the system's capabilities, and we exploit the SSI's theoretical features to get an efficient implementation that will be integrated into the cloud-based platform. This pipeline is here presented considering data collected from a monitoring campaign on the "Matilde donjon" in Livorno (Italy) and reporting preliminary numerical results on the identification of the modal parameters.Source: EVACES 2023 - International Conference on Experimental Vibration Analysis for Civil Engineering Structures, pp. 610–619, Milano, Italy, 30-08/01-09/2023 DOI: 10.1007/978-3-031-39109-5_62 Metrics:
From structural health monitoring to finite element modeling of heritage structures - The Medieval Towers of Lucca Azzara R. M., Girardi M., Padovani C., Pellegrini D. This chapter describes the experiments carried out on three medieval masonry towers in the historic center of Lucca, Italy. The towers have been continuously monitored by high-sensitivity seismic stations that record the structures' response to the dynamic actions of the surrounding environment. Special attention is devoted to the Guinigi Tower, one of the most iconic monuments in Lucca, whose monitoring campaign started in 2021. The goal of the chapter is to show the effectiveness of dynamic monitoring as a valuable source of information on the structural properties of the towers and sketch the capabilities of experiment-based finite element modeling.Source: Data Driven Methods for Civil Structural Health Monitoring and Resilience. Latest Developments and Applications, edited by Mohammad Noori, Carlo Rainieri, Marco Domaneschi, Vasilis Sarhosis, 2023 DOI: 10.1201/9781003306924-7 Metrics:
A digital twin-based platform for structural health monitoring: preliminary results Girardi M., Padovani C., Pellegrini D. This paper describes the preliminary results of the REVOLUTION project, focused on designing and implementing an open-source, digital twin-based platform for the structural health monitoring of architectural buildings and infrastructures. The platform leverages several technologies, such as 2D/3D digitalization techniques, sensor networks, numerical modelling, and damage detection algorithms. Integrating such technologies will allow us to build accurate digital twins of historical buildings, monitor their dynamic properties, model their mechanical behaviour, detect damages and anomalies and plan intervention strategies.Source: BUILding a Digital Twin: requirements, methods, and applications, pp. 53–55, Roma, Italy, 19-20/10/2023
The influence of deflections on the static and dynamic behaviour of masonry columns Girardi M., Padovani C., Pellegrini D. This paper studies the influence of bending deflections on the structural behaviour of masonry columns. Some explicit solutions are presented, and the combined effects of the constitutive and geometric nonlinearities are investigated through an iterative numerical procedure. The results show that considering second-order effects affects both the collapse load and the dynamical properties of masonry beams significantly.Source: European journal of mechanics, A, Solids (Print) 94 (2022). doi:10.1016/j.euromechsol.2022.104570 DOI: 10.1016/j.euromechsol.2022.104570 Metrics:
Dynamic monitoring of a tunnel-like masonry structure via WSN Bartoli G., Betti M., Girardi M., Padovani C., Pellegrini D., Zini G. This paper reports an application of wireless sensor network technology to the long-term monitoring of a historic masonry tunnel-like structure located in Italy. The monitoring was performed within the activity of a research project aimed at providing a general framework to check the structural health of heritage structures and to real-time detect any potential damage that may compromise their safety. The tunnel-like structure was selected being, to the best of authors' knowledge, a challenging experiment both for the type of structure itself and for the technical solution to be employed for installing the monitoring system. This paper, after a brief description of the installed monitoring system and the design of the sensor layout, summarizes the lesson learned after one year of monitoring.Source: Proceedings of the Institution of Civil Engineers. Structures and buildings (2022). doi:10.1680/jstbu.21.00082 DOI: 10.1680/jstbu.21.00082 Metrics:
Dynamic behaviour of the carillon tower in Castel San Pietro, Italy Azzara R. M., Girardi M., Padovani C., Pellegrini D. The paper presents the experimental investigations conducted on the carillon tower of the Santissimo Crocifisso Sanctuary in Castel San Pietro (Bologna, Italy) and the analysis of data collected by velocimeters and accelerometers installed on the structure. The main goal is to assess the effects of the swinging bells on the dynamic behaviour of the tower. The paper's novelty relies on the kind of structure monitored, and the approach followed. The structure is a rare example of a carillon tower, subjected to a careful measurement campaign never carried out before. Moreover, the experimental results are complemented by numerical simulations of the dynamic behaviour of the tower subjected to the action of a swinging bell.Source: ISTI Research reports, 2022
Structural health monitoring for architectural heritage: case studies in Central Italy Azzara R. M., Girardi M., Occhipinti M., Padovani C., Pellegrini D., Tanganelli M. Structural health monitoring (SHM) has been recognized as a useful tool for experimentally assessing the structural behavior of historical buildings over time. If monitoring is performed continuously and for a long time, it allows to evaluate variations in the building's dynamic response to external factors. The main goal is to estimate the dynamic response of the monitored buildings to daily stresses produced by environmental and anthropogenic factors (variations in ambient temperature and humidity, wind velocity, vibrations produced by vehicular traffic or other anthropogenic noise sources including visitors, service staff, etc.) to distinguish ordinary fluctuations in the buildings' response from other anomalous behavior. Continuous monitoring also makes it possible to assess the impact of extraordinary events such as extreme weather events, earthquakes, excavations, cultural events involving many people nearby the monitored buildings. Some examples from the authors' many monitoring campaigns on monuments located in different urban environments are presented. In particular, the effect on one of the monitored buildings of the drastic reduction of seismic noise during the SarsCov2 pandemic lockdown is investigated.Source: EWSHM 2022 - European Workshop on Structural Health Monitoring, pp. 3–12, Palermo, Italy, 4-7/07/2022 DOI: 10.1007/978-3-031-07254-3_1 Metrics:
Dynamic characterization of the Tower of Palazzo dei Vicari in Scarperia (Italy) during and after the 2019 Mugello seismic sequence Azzara R. M., Cardinali V., Girardi M., Marini F., Padovani C., Pellegrini D., Tanganelli M. The paper presents the first results of an experimental campaign conducted on the Tower of Palazzo dei Vicari, in Scarperia, Italy. The Tower is a slender medieval structure located at the corner of the main façade of Palazzo dei Vicari. Over the centuries, both Tower and Palace have undergone several severe earthquakes; therefore, they have been reinforced with steel tie rods. In 2019 the structure was hit by the Mugello seismic sequence, which occurred between 9th December 2019 and the first half of January 2020. The mainshock was registered as 4.5 ML, with an epicenter 5 km far from the city of Scarperia. The earthquake was felt in Toscana and Emilia Romagna Regions and caused some damage in the area's cities. During the seismic sequence, two seismometers were installed on the Tower to record earthquakes and natural vibrations and evaluate the behavior of the structure under seismic loads. A second monitoring experiment has been more recently performed, in June 2021. Eight seismic stations were deployed along the height of the Tower, to achieve a complete dynamic identification of the structure. The ambient vibration tests before and after the seismic sequence made it possible to exclude the presence of damage and to calibrate the numerical model of the Tower via model updating techniques.Source: SEMC 2022 - Eighth International Conference on Structural Engineering, Mechanics and Computation, pp. 215–220, Cape Town, South Africa, 5-7/09/2022 DOI: 10.1201/9781003348443-34 Metrics:
Deep learning for structural health monitoring: an application to heritage structures Carrara F., Falchi F., Girardi M., Messina N., Padovani C., Pellegrini D. Thanks to recent advancements in numerical methods, computer power, and monitoring technology, seismic ambient noise provides precious information about the structural behavior of old buildings. The measurement of the vibrations produced by anthropic and environmental sources and their use for dynamic identification and structural health monitoring of buildings initiated an emerging, cross-disciplinary field engaging seismologists, engineers, mathematicians, and computer scientists. In this work, we employ recent deep learning techniques for time-series forecasting to inspect and detect anomalies in the large dataset recorded during a long-term monitoring campaign conducted on the San Frediano bell tower in Lucca. We frame the problem as an unsupervised anomaly detection task and train a Temporal Fusion Transformer to learn the normal dynamics of the structure. We then detect the anomalies by looking at the differences between the predicted and observed frequencies.Source: AIMETA 2022 - XXV National Congress of the Italian Association of Theoretical and Applied Mechanics, pp. 581–586, Palermo, Italy, 4-8/09/2022 DOI: 10.21741/9781644902431-94 Metrics:
Ambient vibrations of the San Frediano bell tower in Lucca Azzara R. M., Girardi M., Padovani C., Pellegrini D. The San Frediano bell tower in Lucca, dating back to the thertheenth century, is located in the historic center of Lucca and is about 50 m high. The vibrations of the tower, subjected to ambient noise, were recorded from October 27th 2015, to September 9th 2017, using four three axial velocimeters installed at different positions along the tower's height. Data have been acquired continuously with a frequency of 100 sps.
Ambient vibrations of the Guinigi tower in Lucca Azzara R. M., Girardi M., Padovani C., Pellegrini D. The Guinigi tower is located in the historic center of Lucca and dates back to the fourtheenth century. The vibrations of the tower under ambient noise were continuosuly measured from June 25th 2021 to September 13th 2022 via four three-axial velocimeters installed at different positions along the tower's heigth. Data were acquired at 100 sps.